99 OBSERVATIONS ON FOSSIL VEGETABLES, 
which are destitute of capsules, receive directly the action of the fecundating 
substance, and their stems differ in many respects from those of the true 
Dicotyledones. 
V. MONOCOTYLEDONOUS PHANEROGAMIC PLANTS. 
In this class, the female organs of reproduction consist of ovules con- 
tained in an ovarium, which transmits to them the influence of the fecun- 
dating fluid; the embryo has only a single cotyledon; the stem is herba- 
ceous, bulbiform, or arborescent, is formed of fibro-vascular fasciculi, is de- 
veloped by its central part, and is destitute of,oncentric rings or distinct 
bark. 
To this class belong the Graminece, Junceee, Cyperacee, Liliacee, 
Palms, &e. 
VI. DICOTYLEDONOUS PHANEROGAMIC PLANTS. 
The female organs of reproduction are of similar structure to those of 
the last class. 'The embryo has two cotyledons. The stem is herbaceous, 
or woody, and in the latter case is formed of concentric layers, and receives 
its development from the exterior. 
This class contains the greater part of the more ordinary vegetation of 
the present epoch. 
Of the fossil species which I have examined, with reference to their in- 
ternal organization, none belong to the first three classes. 
Hitherto, the attention of geologists has been exclusively confined to 
the external forms of fossil plants; and these forms, illustrated by reference 
to living species, and to vegetable anatomy, have afforded characters by 
which numerous species and genera may be distinguished with accuracy. 
But the supposed destruction of the internal structure of most fossil plants, 
and the difficulty of applying the microscope to those which evidently retain 
it, have hitherto prevented our becoming acquainted with the organization 
of these plants. Many fossil vegetables are converted into a mass of car- 
